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AIR-TO-WATER HEAT PUMP SYSTEMS
ANSWERS TO TEXTBOOK QUESTIONS AND EXERCISES
1. The source is the low temperature material from which heat is absorbed. The sink is the
3. A pilot solenoid valve within a reversing valve controls the direction of movement of a
slide mechanism moved by refrigerant pressure. When the heat pump is in heating mode,
4. A superheated refrigerant is at a temperature above its saturation temperature
6. 5,000 watts
9. 13.5
11. (a) decreases
12. An on/off air to water heat pump may not require a buffer tank if it is not combined with
14. The black line shown in the sketch represents the net curve.
15. A flow switch to monitor flow through an air-to-water heat pump is necessary to verify
16. The air discharge from one heat pump would be at the same temperature as the air intake
17. 48 gallons
18. When the system is in heating mode, the piping design must allow heated water from the
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cooler water returning from the load is reintroduced near the bottom of the tank. When
the system operates in cooling mode, these flow directions must all be reversed.
19. The use of an outdoor reset controller can allow the buffer tank temperature to drop
20. [Please note: In the first printing of the text, this question incorrectly references Figure
13-50a. The correct figure to use to answer this question is Figure 13-55a. This will be
corrected in later printings of the text.]
21. [Please note: In the first printing of the text, this question incorrectly references Figure
Student answers will vary. An on/off heat pump replaces the modulating heat pump. This
22. If the heat pump’s internal expansion tank is not sufficient to handle the system’s total